I tried all three and for me it was very easy to punch in the old Vox AC-30 & AC -15 tones just like my own little VT-30. The differences are in power, physical size and weight. The amplifier controls are the same on all models so what you need to decide is how much power you want. If you're playing only at home, the VT-40 with it's 10" speaker is more than adequate and is loud enough for a small gig. The next one up, the VT-80 is the one I would buy as it's plenty loud enough to gig with the band and easy to carry as it has a single 12" speaker. The big VT-120 houses 2 x 12" speakers and is good for any gig. I didn't try the VT-20, but for use indoors that would be plenty.
The sounds are identical to what my own VT-30 produces and more, with more options.
At the price of any of them you are on a winner. I played everything from Shadows to Jazz to Gary Moore and the sounds were impressive, I would not hesitate to buy one should I need an amp. I used a Squier Classic Vibe and a USA Standard Strat, each sounded stunning.
With the Zoom G3x you will achieve the sound that I got on my recent recordings.


